I/O Support in Cyclone Devices

Cyclone® devices support differential I/O standards, such as LVDS and reduced swing differential signaling (RSDS), as well as single-ended I/O standards, such as LVTTL, LVCMOS, SSTL, and PCI, commonly used for interfacing with other devices on the board.

Differential I/O Standards in Cyclone Devices

Cyclone devices provide support for LVDS and RSDS on up to 129 channels. Cyclone devices can interface with LVDS signals using differential LVDS buffers capable of data transfer rates as high as 640 megabits per second (Mbps). The LVDS buffers in Cyclone devices maintain signal integrity, provide low electromagnetic interference (EMI), and consume less power compared to single-ended I/O standards. Figure 1 shows the LVDS interface in Cyclone devices.

Figure 1. LVDS Interface in Cyclone Devices

Note to Figure 1:

  1. The resistor network is external to the Cyclone device.

Table 1 lists the number of LVDS and RSDS data channels and performance available on Cyclone devices.

Table 1. Number of LVDS Channels Per Cyclone Device

DevicePackageLVDS Channels PerformanceRSDS ChannelsPerformance
EP1C3144-pin TQFP (1)34640 Mbps34311 Mbps
EP1C4324-pin FineLine BGA®103640 Mbps103311 Mbps
400-pin FineLine BGA129640 Mbps129311 Mbps
EP1C6144-pin TQFP29640 Mbps29311 Mbps
240-pin PQFP (2)72640 Mbps72311 Mbps
EP1C12240-pin PQFP66640 Mbps66311 Mbps
324-pin FineLine BGA103640 Mbps103311 Mbps
EP1C20324-pin FineLine BGA95640 Mbps95311 Mbps
400-pin FineLine BGA129640 Mbps129311 Mbps

Notes to Table 1:

  1. TQFP = thin quad flat pack
  2. PQFP = plastic quad flat pack

Single-Ended I/O Standards in Cyclone Devices

To interface with other devices on a board, Cyclone devices support single-ended I/O standards such as LVTTL, LVCMOS, SSTL-2, SSTL-3, and PCI. Single-ended I/O standards provide more current drive capacity than differential I/O standards, and they are critical when working with advanced memory devices such as double-data rate (DDR) SDRAM and FCRAM devices. Table 2 lists the single-ended I/O standards supported in Cyclone devices.

Table 2. Cyclone Device Single-Ended I/O Standard Support

I/O StandardPerformanceTypical Application
3.3-V/2.5-V/1.8-V LVTTL250 MHzGeneral Purpose
3.3-V/2.5-V/1.8-V/1.5-V LVCMOS250 MHzGeneral Purpose
SSTL-3 Class I & II166 MHzSDR SDRAM
SSTL-2 Class I & II133 MHzDDR SDRAM & FCRAM
3.3-V PCI66 MHzPC & Embedded
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